Nitinol, a shape memory alloy, provides a unique combination of properties which is particularly suited for medical devices. It is the material of choice for many stenting applications in treatment of vascular diseases. At the present time, there is no software available for mathematical modeling of thermomechanical behavior of Nitinol. The specific objective of this work is: To develop a CAD system based on mathematical models of Nitinol that can predict the mechanical response of medical devices under in vivo and in vitro conditions. To develop mathematical models of living tissues which are in contact with these devices, and to model the interactions (contact) between the medical devices and the living tissues in the context of nonlinear finite element. To design and fabricate new Nitinol stents with different design parameters for carotid, iliac and femoral applications utilizing the developed CAD system. To perform in vitro experimental studies for characterization of material parameters of Nitinol and the above arteries which are needed for mathematical modeling and verification of the software. To perform in vivo animal studies to examine acute and chronic response of the above arteries to various stent designs and to examine critical design parameters for Nitinol stents. PROPOSED COMMERCIAL APPLICATION: There are several potential commercial opportunities in this work. The market for stenting of various arteries is rapidly increasing and many biomedical companies will be very interested in this software. The software can be used for design of new medical devices, particularly Nitinol stents, with improved performance and higher reliabilities targeted for specific applications.